An international service will remember the loss off its coast around a century ago of two British troop ships carrying American soldiers to fight alongside the Allies.
The people of Islay and Jura who died while serving in the First World War will also be honoured during the special day.
The sinking of SS Tuscania in February 1918 and HMS Otranto in October 1918 off the coast of Islay saw around 700 US servicemen and British crew members lose their lives.
Carrying more than 2,000 US Army personnel to join battlefields in Europe, SS Tuscania was on its way from New Jersey to Liverpool when it was torpedoed by a German submarine, causing it to sink between Islay and Northern Ireland.
Just eight months later, HMS Otranto sank near Machir Bay, on the west coast of the inner Hebridean island, following a collision with HMS Kashmir.
Many lives were saved in heroic rescue missions, but hundreds of American troops and British crew members still perished. Around 210 people from the Tuscania died and 470 from the Otranto lost their lives, with many washing up on Islay’s shoreline.
Friday has been designated as a WW100 Scotland day of commemoration on Islay, with a commemorative service and wreath-laying ceremony due to take place at the Port Ellen war memorial.
The day’s events will remember the valiant rescue efforts of the local community when the troop ships went down, and their work to give the dead proper burials.
Joining Princess Anne and Ms Sturgeon at the ceremony will be dignitaries representing the US, France and Germany.
Scottish and American descendants of those caught up in the tragic events of 1918 are also expected to attend, along with descendants of the local men who went to war.
Scotland’s Culture Secretary Fiona Hyslop, said: “World War One had a devastating impact across Scotland with no town or village unaffected.
“Islay and Jura not only lost a significant amount of men for such a small community, they had war brought to their shorelines.
“It is a real testament to the people of the islands how they responded to those tragedies and the depth of compassion shown to those American troops and British crew men who were caught up in the sinkings of the Tuscania and Otranto.”